Power, Heat, Noise, And Efficiency
Our power readings represent the entire test system, and our platform (excluding graphics) consumes roughly 48 W at idle and 96 W under full load. Additionally, the power supply draws about 11% off the top of every power reading, so we wanted to make it clear to readers that none of these cards can draw more than 200 W.
Remember that of this comparison’s samples, only the MSI GeForce GTS 450 has an auxiliary PCIe power cable connection. The Afox Radeon HD 6850 draws more energy, however. The indication to us is that the GeForce GTS 450 might not have needed the six-pin connector were it not for backward slot compatibility.
We think the presence of overkill power connectors on reference-designed graphics cards is an effort by GPU manufacturers to assure the highest level of compatibility. According to the PCI-SIG, some early boards only supported 75 W of power through first-gen PCIe slots.
Of course, most buyers won’t spend $200 on a graphics card simply to put it in a heavily-outdated system. Given the facts and power consumption stats above, we can only guess that a pair of Afox Radeon HD 6850 cards in CrossFire might not get adequate power from some more modern motherboards, and that guess corresponds to the proliferation of auxiliary power connectors on some of the same motherboards. Yet, buyers who have room for a pair of cards will likely purchase double-slot cards instead. Afox’s design is thus acceptable, if controversial.
FurMark pushes the thermal limits of a graphics card, and users need to keep their case temperature below 35° Celsius to test with it. That is, unless those users prefer the less-expensive GeForce GT 440.
Small fans must spin quickly to keep mid-sized graphics processors cool. The speeds that produce these noise levels are also detrimental to longevity, so the warranty periods on page one are particularly noteworthy. We'd like to see Afox augment its 12-month coverage with another couple of years.
In games, the biggest detriment to system efficiency is the overhead power for parts that support the GPU. With system overhead relatively consistent, the card that draws the least power also has the lowest gaming efficiency due to its reduced performance.